Scattered thunderstorms developed in a warm and very humid airmass across central Pennsylvania during the late afternoon and evening of June 15, 2017. These storms produced a handful of reports of wind damage across the western highlands of Pennsylvania.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS CTP wrote it up.
Scattered thunderstorms developed in a warm and very humid airmass across central Pennsylvania during the late afternoon and evening of June 15, 2017. These storms produced a handful of reports of wind damage across the western highlands of Pennsylvania. Johnstown reported 1.85 of rain in 20 minutes which resulted in localized flash flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS State College, PA wrote its last area forecast discussion before the first event at Jun 15, 2:48 PM EST, 2 hours 20 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 348 PM EDT Thu Jun 15 2017 .SYNOPSIS... A front stalled over southwestern PA will lift to the northeast as a warm front today and Friday. This will keep the mention of showers and thunderstorms in the forecast into the weekend. Heavy rain is possible later today and tonight. A cold front will push through early next week and lower the humidity and temperatures for the middle of next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Showers and thunderstorms firing off the Allegheny ridges are being aided by convergence along a warm front across the region and lift from approaching short wave aloft. Convection will continue into the evening hours with the overall area expected to shift southeast while most individual cells move generally to the northeast. A second ling of storms is also developing farther west in Eastern Ohio which is expected to progress into Relatively slow moving storms within an area of high sfc moisture will present a threat for heavy rain into the evening hours. Earlier outlook from WPC for MRGL risk of rainfall exceeding FFG over the western half of the area today and tonight, has been upgraded to a SLGT risk across parts of northcentral PA. While most flash flood guidance is better than 2"/3 hrs in the west and more than 3"/3hrs in the central mountains and even higher in the east, with western part of CWA with the moisture axis, have issued a Flash Flood Watch through the evening hours. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Showers/storms are more than likely tonight for most of the area. The SE may continue to stay dry all night. The threat for heavy rain is greatest tonight when the deep moisture plume gets farther into the area. Thus far, it has remained to our west. The 1.5+" PWATs will be in place and there will be a period of time this evening and early tonight when the relative inflow of moisture will match/balance the storm motion. This can lead to heavy rainers. But, with no specific locations primed with very wet soil, still some time to go, and some uncertainty of where heavy rain is most likely, no flash flood watch will be issued on this shift. The day shift will have a better look at it as the meso models/CAMs begin to reach into that time frame. At this point, the NAM drops point amounts of 2+" QPF in the W and NC mtns. The GFS is lower and more washed out on the QPF amounts. Will hold basin-average QPF to around an inch total in the west and NC mtns. Will continue to mention heavy rain in the wx grids. The most potent trough aloft will be off to the east by sunrise, and forcing wanes. But, lingering boundaries could be foci for SHRA/TSRA on Fri. The LI's don't get negative in the northeast on Fri per the NAM and GFS, but dewpoints still high in the east and south, and the CAPE is again progged to be above 1000joules. Will continue to mention thunder with the entire area in general thunder on the SPC Day2 prog. Expect temps to be a little warmer on Friday in the west where it may dry out in the afternoon. The sparse coverage of showers/storms on Friday should preclude any further worries of flooding. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Model and ensemble guidance remain in good agreement on the development of a modestly strong mid/upper level trough over the Great Lakes by Monday, with multiple waves progressing around the base of the trough and ejecting northeast into Canada. The most likely period for showers and thunderstorms (Sun-Mon) will focus along the associated surface cold front which is progged to slowly push southeast and reach the Mid Atlantic coast by 20/12z. Precipitation will be focused mainly to the west of the Appalachians on Sunday before shifting east on Monday. Temperatures are fcst to trend above average over the weekend with max readings in the mid 80s to low 90s on Sunday. Max heat index is projected to reach the mid/upper 90s across portions of the mid- lower Susquehanna Valley. Unlike the recent heat episode, the duration of hot temperatures will be shorter and last 2 days at most (limited area-SEPA). Lower humidity and near average temperatures are likely following the cold frontal passage into the middle part of next week. Another shortwave is fcst to rotate through the trough around midweek before the upper level pattern turns more zonal by the end of next week. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... Scattered showers/storms will affect the western and central TAF sites through the afternoon and early evening hours and possibly eastern TAF sits by later this evening. Deteriorating cigs appear likely tonight, as moist southeast flow, rainfall from earlier today, and residual showers affect the region. Latest SREF guidance support widespread MVFR cigs by late evening and IFR cigs possible early Friday morning. .OUTLOOK... Fri...Low cigs, showers/tstorms possible, mainly in the AM. Sat...AM fog possible. Sun...Patchy AM fog poss east. PM tsra impacts poss west. Mon and Tue...Tsra impacts possible. && .CTP WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch until midnight EDT tonight for PAZ004>006- 010>012-017-018-024-025-033-034. && SYNOPSIS...Gartner NEAR TERM...Gartner SHORT TERM...Dangelo/Gartner LONG TERM...Steinbugl AVIATION...Gartner
Hazardous Weather Outlook...UPDATED National Weather Service State College PA 1234 PM EDT Thu Jun 15 2017 PAZ004>006-010>012-017-018-024-025-033-034-161645- Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield- Northern Centre-Cambria-Blair-Somerset-Bedford- 1234 PM EDT Thu Jun 15 2017 ...FLASH FLOOD WATCH IN EFFECT UNTIL MIDNIGHT EDT TONIGHT... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...This Afternoon and Tonight. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Flash Flood Watch. Strong to severe thunderstorms with gusty winds are possible during the afternoon and evening. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ019-026>028-035>037-041-045-046-049-050-161645- Southern Centre-Huntingdon-Mifflin-Juniata-Fulton-Franklin-Tioga- Northern Lycoming-Southern Clinton-Southern Lycoming-Union-Snyder- 1234 PM EDT Thu Jun 15 2017 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...This Afternoon and Tonight. Strong to severe thunderstorms with heavy rain and gusty winds are possible during the afternoon and evening. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ042-051>053-056>059-063>066-161645- Sullivan-Montour-Northumberland-Columbia-Perry-Dauphin-Schuylkill- Lebanon-Cumberland-Adams-York-Lancaster- 1234 PM EDT Thu Jun 15 2017 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...This Afternoon and Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather.
The State College radar (KCCX), 57 km away, was scanning. The volume nearest the first event began at 22:06 UTC.
4 thunderstorm wind, 4 flash flood. Local standard time, as filed.
A severe thunderstorm producing winds estimated near 60 mph knocked down tree and wires along Home Camp Road in Union Township.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree and wires on Ash Street.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree across a roadway.
A twenty minute rainfall total of 1.85 inches was reported at Johnstown. This brought rapid flash flooding to the area. Most of the flooding occurred in Johnstown, with reports of flooding in Upper Yoder Township, Southmont and Westmont. No injuries were reported. A car was trapped in the flooding with several people inside it on Iron Street. The occupants escaped the waters before emergency help arrived. In additions to numerous flooded roadways, many basements flooded as well. A sampling of roads flooded included Mount Airy Drive in Richland Township, Fairfield Avenue, Grove Avenue, and Osborne Street in Johnstown. Gilbert Street in Brownstown and Berkley Road in Upper Yoder Township.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree across a roadway.
Heavy rain produced an earth slide on Dunnings Highway near Showalters Road.
Flash flooding occurred, impacting Zion Back Road in Walker Township.
Similar to the flash flood the night before, Johnstown received 1.16 inches of rain in 15 minutes. This brief downburst produced more localized flash flooding in the Johnstown area. Several roads were closed and basements were flooded.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2017Every state in 2017This day in weather historyWarnings in Pennsylvania, June 2017
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 694866, 694867, 694868, 699152, 694870, 699147, 699148, 699150.